Lumia 720 "other" memory issue! Help! Update OS WP?!

[WPCentral Question]

Hi! Everyone!
I have Lumia 720. And recently i had memory issue. It turned out that "other" memory in the storage increase rapidly. So, according to articles that I've read. I should do factory reset. And. . . it had another issue with the spinning gears. I'd fixed it by going to the Nokia Care Center.
Everything back to normal. But, after 1 month or so, the issue is back now. I'm going crazy because of that.
I read in WPcentral to avoid same issue, i have to update the software. my question is,
can i update my software WP 8.0 into WP 8.2 or WP 8.3 in Lumia 720?

And, another issue again with my External memory, it can't read pictures and i have to give some free space in "internal memory" so the pictures can be read in external memory. it's so weird.

it's super annoying! I love Nokia so much, but this gives me a nasty headache! Ugh!
PLEASE!! HELP!!!

Thank you!!

 

[Pacus1x]

With WP8.1 you can install and move your apps in the micro SD and that way saving space for the internal memory.

If the internal memory gets full, it will difficult for the phone to operate correctly since it needs a minimum space for the file swapping.

You can try to clean the "other" stuff with this app. Maybe that app can solve that problem.

 

[Nur Akifah Taslim]

I'd already done with the app. but, it didn't suit with my phone. may be because the OS.
Can i upgrade my OS? my phone is Lumia 720. can i still upgrade it without problem?

Thanks!